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ISSN 2664-2441 (Online)
ISSN 2073-9583 (Print)

Features of heat-resistant properties of metal of not-rolled boilertubes produced from continuously cast billets of steel 20

Metalozn. obrobka met., 2020, vol. 26 (93), 49-58

L.V. Opryshko, Head of the Laboratory of Pipes and Products for Thermal and Nuclear Energy, Liudmila.opryshko@gmail.com
T.V. Golovnyak, Head of the sector for expert research of metal products from ferrous and non-ferrous metals and alloys, tatyana.golovniak@gmail.com

State Enterprise Ya.Yu.Osada Research and Design-Technology Institute of Pipe Industry, Ukraine, Dnipro
UDC 621.182+621.7]:669.018.44 

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For the first time, long-term strength (the main design characteristic of power generating equipment) of metal of hot-rolled boiler tubes manufactured with various reductions on a tube rolling unit with a continuous mill (TPA 30-102) of INTERPIPE NIKO TUBE LLC from non-deformed continuously cast steel 20 billets of a new manufacturer (MZ DNIPROSTAL LLC) was studied. Structure and fracture pattern were studied in tests for heat-resistance of tube samples in various states (after hot rolling and after normalizing). Influence of structural characteristics and technological factors of production of tube billets and tubes on the level of long-term strength of metal of the experimental tubes was established. It was shown that presence of a developed zone of columnar crystals (transcrystallization zone) in the billet macrostructure and the technology of heat treatment of boiler tubes used at the tube producing plant do not enable obtaining of a relatively uniform structure and an optimal level of long-term strength and ductility in the tube metal. This is especially true for the tubes made with low reductions.
The need for improving the technology of production of continuously cast billets at MZ DNEPROSTAL LLC and the technology of heat treatment of tubes made from these billets at INTERPIPE NIKO TUBE LLC was established. For optimal combination of long-term strength and long-term ductility of metal of hot-rolled boiler tubes, it is necessary to obtain a developed zone of equiaxed crystals and a limited zone of columnar crystals in macrostructure of initial undeformed continuously cast billets. Necessity of standardizing the macrocrystalline metal structure of undeformed continuously cast boiler billets in TU U 24.1-05757883-216 Round Continuously Cast Steel Billet for the Manufacture of Boiler Tubes was established.
Possibility of using steel 20 boiler tubes made from MZ DNIPROSTAL LLC billets on the tube rolling unit TPA 30-102 with reductions not less than 17.0 in a state after hot rolling (without mandatory normalizing from separate heating) was demonstrated at boiler units of thermal power plants (heat electropower stations).

Keywords: non-deformed continuously cast billet, macrocrystalline structure, boiler hot-pressed tubes, microstructure, high-temperature strength, microstructure, ultimate long-term strength, long-term ductility, fracture, fracture form.


  1. Krutasova E. I. Nadezhnost metalla energeticheskogo oborudovaniia (Reliability of metal power equipment), Moscow: Energoizdat, 1981, 240 p. [in Russian].
  2. Bugai N.V. Rabotosposobnost i dolgovechnost metalla energeticheskogo oborudovaniia (Performance and durability of metal power equipment), Moscow: Energoatomizdat, 1994, 272 p. [in Russian].
  3. Кumanin V.I., Kovaleva L.A., Alekseev S.V. Dolgovechnost metalla v usloviiakh polzuchesti (Creep durability), Moscow: Metallyrgia, 1988, 224 p. [in Russian].
  4. Antikain P.A. Metally i raschety na prochnost kotlov i truboprovodov (Metals and calculation for the strength of boilers and piping), Moscow: Energoizdat, 1990, 386 p. [in Russian].
  5. Lanskaia K. A. Zharoprochnost stali (Heat resistance steel, Moscow: Metallyrgia,1969, 247 p. [in Russian].
  6. Opryshko L.V. Novye energosberegaiushchie tekhnologii proizvodstva trub dlia energetiki (New energy-saving technologies for the production of tubes for power systems), Proceeding of the ХIХ International  Conference “Problems of energy conservation, safety, ecology in industrial and municipal energy”, Yalta: Assotsiatsiia teploenergeticheskikh kompanii Ukrainy, 2006, pp. 72-74 [in Ukraine].
  7. Opryshko L.V. Perspektivy ispolzovaniia nedeformirovannoi nepreryvnolitoi zagotovki dlia proizvodstva kotelnykh goryachedeformirovannuh trub iz uglerodistoi stali (The outlook of using non-worked continuously cast billets in the production of hot-worked boiler tubes of carbon steel) Proceeding of the International Scientific and Technical Conference “Modern trending production of welded and seamless tubes and pipe: technologies and equipment”. Kyiv: Truby Ukrainy, 2008, pp. 101-105 [in Ukraine].
  8. Opryshko L.V., Poltava I.I., Metallurgicheskaia i gornorudnaia promyshlennost, 2010, No. 4, pp. 53-57 [in Ukraine].
  9. Opryshko L.V., T.V.Goloviak, Gerasimenko P.V. Metallurgicheskaia i gornorudnaia promyshlennost, 2015, No. 3, pp. 40-44 [in Ukraine].
  10. Opryshko L.V., T.V.Goloviak, Poltava I.I. Metallurgicheskaia i gornorudnaia promyshlennost, 2016, No. 1, pp. 60-61 [in Ukraine].
  11. Zimovets V.G., Kuznetsov V.U. Sovershenstvovanie proizvodstva stalnyh trub (Improving the production of steel pipes), Moscow: MISIS, 1996, 480 p. [in Russian].
  12. Onishchenko I.I., Kutsenko P.I., Kutsenko A.I. Teoria nepreruvnoi prokatki (Theory of continuous rolling), Zaporozhie: ZGIA, 1998, 470 p. [in Ukraine].
  13. Chikalov S.G. Proizvodstvo bezshovnyh trub iz nepreryvnolitoi zagotovki (Production of seamless tubes from continuously cast billet), Volgograd: Press and information committee, 1999, 416 p. [in Russian].
  14. Opryshko L.V., Lube I.I. Metallurgicheskaia i gornorudnaia promyshlennost, 2006, No. 6, pp. 57-60 [in Ukraine].
  15. Opryshko L.V., Teoriіa i praktika metallurgii, 2010, No. 5-6, pp. 124-126 [in Ukraine].
  16. Opryshko L.V., Perepelytsia Т.V, Gerasimenko P.V., Metaloznavstvo ta obrobka metaliv, 2012, No. 4, pp. 3-9 [in Ukraine].
  17. Opryshko L.V., Goloviak T.V., Gerasimenko P.V., Metaloznavstvo ta obrobka metaliv, 2015, No. 1, pp. 3-9 [in Ukraine].
  18. Opryshko L.V., Goloviak T.V., Gerasimenko P.V., Metaloznavstvo ta obrobka metaliv, 2016, No. 1, pp. 54-59 [in Ukraine].
  19. Opryshko L.V., Goloviak T.V., Poltava I.I., Metallurgicheskaia i gornorudnaia promyshlennost, 2019, No. 1-2, pp. 46-53 [in Ukraine].
  20. Opryshko L.V., Goloviak T.V., Poltava I.I., Stal, 2019, No. 10, pp. 40-44 [in Russian].